⏵ Course guide · Mount St. Helens single-track
The Bigfoot 20 Mile runs 100% single-track along Mount St. Helens' southwest side, through lava fields, stream crossings, and old-growth forest on a volcano that erupted in 1980. I will walk you through the terrain first, then give you a pacing and fueling plan for a technical single-day distance. There are free calculators along the way to dial in your own numbers.
These facts come from the official Destination Trail event page. Check the current year details, cutoffs, and aid stations before you commit. Race logistics change year to year.
The Bigfoot 20 Mile begins at Marble Mountain Sno Park and runs entirely on single-track along Mount St. Helens' southwest side, a landscape still shaped by the 1980 eruption.
Runners cross open lava fields, several stream crossings, and stretches of old-growth forest across the 20 miles. The terrain shifts constantly between exposed volcanic ground and shaded timber, so expect real variety even without a published elevation profile.
Destination Trail runs both the Bigfoot 20 Mile and the much longer Bigfoot 200 on the same Mount St. Helens terrain. If you want a taste of the mountain without the 200 mile commitment, this is the race built for exactly that.
With no published vert and a generous 9 hour cutoff, treat this as a technical-terrain pacing problem rather than a climbing problem.
Volcanic lava field terrain and repeated stream crossings can slow your effective pace well below what a smooth singletrack mile suggests. A grade-adjusted pace target still helps, but factor in extra time for technical footing that a flat pace calculation would not capture.
A 9 hour cutoff for 20 miles gives most trail runners genuine room to finish. Use that margin to run smart on the technical sections rather than rushing through lava fields or stream crossings where a fall costs more time than caution does.
⏵ Free tools to pace this course
Mid-August on Mount St. Helens can run warm through the exposed lava field sections, even with old-growth forest offering some shade elsewhere on course.
Aim for roughly 40 to 60 grams of carbohydrate per hour given the shorter distance, and sodium in the 300 to 700 mg per liter range, leaning higher if the exposed lava field stretches run hot.
The route's stream crossings offer a natural cooling opportunity, but treat your carried hydration as the primary plan and the streams as a bonus, not a substitute for a real fueling strategy.
⏵ Build your fueling plan
Get a carb, sodium, fluid, and caffeine plan per hour built for your weight, your goal time, and a mid-August Mount St. Helens day with the free ultra fueling calculator. Browse the rest of the free running tools at the tools hub.
⏵ Train for it with Summit Line
Get a race-day plan built around YOUR fitness, this Mount St. Helens terrain, and your projected splits. Summit Line reads your real training, builds a plan for technical volcanic single-track, and rehearses your fueling so race day is something you execute, not guess at.
Destination Trail does not publish an elevation gain figure for the Bigfoot 20 Mile, but the course runs 100% single-track along Mount St. Helens' southwest side, through lava fields, stream crossings, and old-growth forest on a volcano that erupted in 1980. The 9 hour cutoff is generous for a 20 mile trail race, which tells you this is built to be a genuinely finishable technical day, not a speed test.
The route begins at Marble Mountain Sno Park and runs along Mount St. Helens' southwest side, taking runners through a landscape shaped by the mountain's 1980 eruption: lava fields, stream crossings, and old-growth forest, all on 100% single-track trail.
For a 20 mile trail race with a 9 hour cutoff, plan for a shorter but real fueling window. Aim for roughly 40 to 60 grams of carbohydrate per hour given the shorter distance, and sodium in the 300 to 700 mg per liter range, especially if mid-August heat shows up on the exposed lava field sections. Build your numbers with the free ultra fueling calculator before race day.
The cutoff is 9 hours for the full 20 miles. Given the technical single-track terrain, lava fields, and stream crossings, this is a generous window that gives most trail runners real room to finish, even at a conservative pace.
Yes. The Bigfoot 20 Mile is run by Destination Trail, the same organizer behind the Bigfoot 200, and shares the Mount St. Helens setting with its longer sibling. It is a genuine entry-distance option if you want a taste of the same volcano terrain without committing to the 200 mile race.
100% single-track, lava fields, and stream crossings make this more technical than a typical first trail race, but the 9 hour cutoff for 20 miles gives a well-prepared newer trail runner real room to finish. If you have some technical trail experience and want a genuine taste of Mount St. Helens terrain, this is a reasonable step up from a groomed park trail race.
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<a href="https://runsummitline.com/guides/bigfoot-20-mile">The Bigfoot 20 Mile course guide</a>This guide is independent and for planning only. The course details, dates, cutoffs, and aid stations come from public sources and can change year to year, so confirm the current specifics with the official race before you register or run. The fueling and pacing advice is general and not medical advice.